共查询到19条相似文献,搜索用时 103 毫秒
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通过(CF~3CO~2)~3Ln(Ln=Nd、Y和Eu)和R^1AlR~2(R^1=H, R=i-C~4H~9;R^1=R=C~2H~5), 反应首次合成和培养出Nd-Al、Y-Al和Eu-Al三种新的双金属稀土配合物和晶体, 并用X射线衍射法测定出它们的晶体结构, 然后再用二维波谱技术, 进一步证实和完善了晶体结构中的价态和非共面现象。由此确定这三种稀土配合物分子式的通式为: [(μ-CF~3CO~2)~2Ln(μ-CF~3CHO~2)AlR~2.2THF]~2。根据实验结果还提出了通过烷基化、β-消除(或氢化)、氢转移、键合及缔合等五个步骤生成这些配合物的反应机理。这些配合物单独可使MMA和ECH催化聚合, 前者可获得主要以间同结构聚合物, 后者聚合催化活性较高, 在极少量的ECH存在下,还可使THF开环聚合, 并通过PTHF端基分析, 提出了羊离子聚合反应机理。 相似文献
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通过(CF~3CO~2)~3Ln(Ln=Nd、Y和Eu)和R^1AlR~2(R^1=H, R=i-C~4H~9;R^1=R=C~2H~5), 反应首次合成和培养出Nd-Al、Y-Al和Eu-Al三种新的双金属稀土配合物和晶体, 并用X射线衍射法测定出它们的晶体结构, 然后再用二维波谱技术, 进一步证实和完善了晶体结构中的价态和非共面现象。由此确定这三种稀土配合物分子式的通式为: [(μ-CF~3CO~2)~2Ln(μ-CF~3CHO~2)AlR~2.2THF]~2。根据实验结果还提出了通过烷基化、β-消除(或氢化)、氢转移、键合及缔合等五个步骤生成这些配合物的反应机理。这些配合物单独可使MMA和ECH催化聚合, 前者可获得主要以间同结构聚合物, 后者聚合催化活性较高, 在极少量的ECH存在下,还可使THF开环聚合, 并通过PTHF端基分析, 提出了羊离子聚合反应机理。 相似文献
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合成了含二氮芴和联吡啶等配体的一系列新型钌铁双核配合物:[(C~1~0H~6N~2)C=N-N=CR-Fc)Ru(bpy)~2]·(PF~6)~2,[(C~1~0H~6N~2)C=N--C~6H~4-N=CR-Fc)Ru(bpy)~2]·(PF~6)~2,[(C~1~0H~6N~2)C=N-C~6H~4-C~6H~4-N=CR-Fc)Ru(bpy)~2]·(PF~6)~2,并对其进行了光谱表征,通过对该类配合物的循环伏安和发光光谱研究,讨论其激发态的氧化还原性和对[Ru(bpy)~3]^2^+发光过程的猝灭作用.研究表明猝灭过程为扩散控制的双分子交换能量传递 相似文献
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含二茂铁基为臂的三角架型过渡金属配合物的研究 总被引:2,自引:0,他引:2
本文利用2,2',2'-三氨基三乙胺(tren)与二茂铁甲醛(FcCHO)的Schiff碱缩合产物(L)为配体合成了十个三角型过渡金属配合物:[MLX]^2+/1+,M=Zn^2+,Cu^2+,Ni^2+,Co^2+=和MN^2+,X=H~2O或OAc^-,并用电子光谱、红外光谱和顺磁=共振光谱对配合物的结构进行了表征.测定了四个化合物的变温磁化率,实验结果表明二茂铁中磁性的Fe(Ⅱ)离子对配合物的磁性影响很小,整个化合物只显示中心离子的磁性. 相似文献
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苯基稀土钆配合物具有Ln-Cσ键,由于这类配合物不稳定且分离困难,故其研究工作开展得很少~[1,2],其电子结构的研究尚未见报道.最近,我们合成了新型的苯基稀土配合物C_6H_5LnCl_2·nTHF(Ln=Pr、Sm、Gd,n=3,4)并测定了其晶体结构~[3],本文报道了苯基稀土钆配合物的电子结构和成键性质,并与中性苯稀土配合物的成键性质~[4]进行了比较. 相似文献
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稀土配合物的研究 IV: 稀土元素与4-酰代双吡唑啉酮BPMPPD及1,10-二氮杂菲三元配合物的合成和性质的研究 总被引:1,自引:0,他引:1
4-酰代双吡唑啉酮是一类新型β双酮多啮金属离子螯合剂和萃取剂, 其性能优于单吡唑啉酮, 本文继合成1,5-双(1'-萃基-3'-甲基-5'-氧代吡唑-4')-1,5-戊二酮(BPMPPD, H2A)后, 又合成了它和1,10-二氮杂菲(Phen, P)与稀土元素形成的三元固态配合物, 并对这些新配合物的性质进行了研究。 相似文献
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A series of binary quasicrystal approximants RE13Zn58+delta (RE = Ho, Er, Tm, and Lu) have been prepared, and structural studies were performed by means of single-crystal X-ray diffraction. All four compounds crystallize in the orthorhombic system, but while the Ho-containing compound crystallizes in space group Pcmn, the rest of the compounds crystallize in Pc21n. This work is a continuation of the structural studies on RE13Zn approximately 58 (RE = Ce, Pr, Nd, Sm, Gd, Tb, and Dy), which all belong to the hexagonal system. The sequence of RE13Zn58+delta compounds exhibits a large variability in local ordering and composition, and therefore the crystal structures are generally rather more complex than those previously reported and exhibit a number of different ordering modes. These four compounds are structurally closely related to each other. 相似文献
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Crystalline samples of rare earth carbodiimides were synthesized by solid-state metathesis reactions of rare earth trichlorides with lithium cyanamide in sealed silica ampules. Two distinct structures were determined by single-crystal X-ray diffraction. The structure determined for Sm2(CN2)3 [C2/m, Z = 2, a = 14.534(2) A, b = 3.8880(8) A, c = 5.2691(9) A, beta = 95.96(2) degrees , R1 = 0.0267, and wR2 = 0.0667] was assigned for RE2(CN2)3 compounds with RE = Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er, and the structure determined for Lu2(CN2)3 [R32, Z = 3, a = 6.2732(8) A, c = 14.681(2) A, R1 = 0.0208, and wR2 = 0.0526] was assigned for the smallest rare earth ions with RE = Tm, Yb, and Lu by powder X-ray diffraction. Both types of crystal structures are characterized by layers of [NCN](2-) ions whose arrangements can be derived from the motif of a closest packed layer of sticks. These layers alternate with layers of rare earth ions in a one-by-one sequence. Different tilting arrangements of the N-C-N-axes relative to the stacking directions (c) and different arrangements of RE3+ ions within metal atom layers account for the two distinct structures in which Sm3+ and Lu3+ ions adopt the coordination numbers 7 and 6, respectively. 相似文献
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稀土异硫氰酸盐与二甲基亚砜配合物的合成,性质及热分析研究 总被引:1,自引:0,他引:1
合成了15种稀土异硫氰酸盐与二甲基亚砜(DMSO)的配合物,经化学分析和元素分析确定其组成为RE(NCS)_s·mDMSO(RE=La,Ce,Pr,Nd,Sm,Eu,Gd;m=5.RE=Tb,Dy,Ho,Er,Tm,Yb,Lu,Y;m=4).用红外光谱及X射线衍射技术进行了表征.运用TG-DTA-DTG联用技术研究了该系列配合物的热分解过程,求算热重动力学参数发现,第一步热分解阶段的活化能随着中心高子——镧系元素原子序数的依次递增呈现“双峰现象”. 相似文献
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稀土离子-1,10-菲罗啉桥联胺二元配合物的稳定性研究 总被引:1,自引:0,他引:1
在(25±0.1)℃,Ⅰ=0.1mol·dm^-3NaClO~4的条件下,用pH电位滴定法测定了配体N,N'-二取代基-1,10-菲罗啉-2,9-二甲胺(LI~I6,取代基分别对于甲基、乙基、正丙基、异丙基、叔丁基)在水溶液中分别与稀土离子Lu[Lu=La(Ⅲ),Ce(Ⅲ),Pr(Ⅲ),Nd(Ⅲ),Sm(Ⅲ),Eu(Ⅲ),Gd(Ⅲ),Tb(Ⅲ),Dy(Ⅲ),Ho(Ⅲ)]的二元配合物的稳定常数,提出了配合物在溶液中的可能结构,对金属离子和取代基的大小对配合物稳定性的影响进行了详细的讨论,动用线性回归,对有放射性的Pm(Ⅲ)与相应配体的二元配合物的稳定常进行了推测。 相似文献
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Eleven new oxides, derived from yttrium barium copper oxide by replacing the square-planar copper [Cu-O4] of the basal plane of the triple perovskite-based structure with octahedral Cr(IV), have been prepared at high pressure and temperature. Their crystal structures have been determined, and their complex microstructure has been established by means of high-resolution electron microscopy and electron diffraction. The materials have a general formula of CrSr2RECu2O8 (RE = La, Pr, Nd, Eu, Gd, Tb, Dy, Y, Ho, Er, and Lu); they are tetragonal, show the symmetry of space group P4/mmm, and do not appear to be superconducting. 相似文献